A researcher wishes to conduct a study of the color preferences of new car buyers. Suppose that 50% of this population prefers the color blue. If 10 buyers are randomly selected what is the probability that exactly 3 buyers would prefer blue? Round to answer to four decimal places

A researcher wishes to conduct a study of the color preferences of new car buyers Suppose that 50 of this population prefers the color blue If 10 buyers are ran class=

Respuesta :

Answer:

0.1172

Explanation:

The probability that a buyer prefers blue = 50% = 0.5

The number of buyers =10

We want to find the probability that exactly 3 buyers would prefer blue.

To solve this problem, we use the binomial distribution formula given below:

[tex]\begin{gathered} P(x=k)=\left(\begin{array}{l}n \\ k\end{array}\right)p^k(1-p)^{n-k} \\ =\frac{n!}{k!(n-k)!}p^k(1-p)^{n-k} \end{gathered}[/tex]

In the given case:

• n=10

,

• k=3

,

• p=0.5

Therefore:

[tex]\begin{gathered} P(x=3)=\frac{10!}{(10-3)!3!}(0.5)^3(1-0.5)^{10-3} \\ =\frac{10!}{7!3!}\times(0.5)^3(0.5)^7 \\ =\frac{10\times9\times8\times7!}{7!\times6}\times(0.5)^3\times(0.5)^7 \\ =\frac{10\times9\times8}{6}\times(0.5)^3\times(0.5)^7 \\ \approx0.1172 \end{gathered}[/tex]

The probability that exactly 3 buyers would prefer blue is 0.1172 (rounded to four decimal places).